Mucositis is a condition characterized by swelling, irritation, and discomfort of mucosal linings such as those of the gastrointestinal tract and the oral and oral pharyngeal cavities, and can result in mouth and throat sores, diarrhea, abdominal cramping and tenderness, and rectal ulcerations. This condition occurs in approximately half of all cancer subjects, and is a common side effect of cancer treatments involving radiation and/or chemotherapy. The goal of these approaches to cancer treatment is to kill rapidly dividing cancer cells but, unfortunately, other rapidly dividing cells are killed by the treatment as well, including cells that line regions such as the gastrointestinal tract, leading to mucositis. Symptoms of mucositis generally occur five to ten days after the start of cancer treatment and can take two to four weeks after cessation of treatment to clear. The incidence of mucositis, as well as its severity, depends on factors such as the type and duration of the cancer treatment. It is also highly prevalent in subjects treated with high dose chemotherapy and/or irradiation for the purpose of myeloablation, in preparation for stem cell or bone marrow transplantation.
Mucositis adversely impacts the quality of life of cancer subjects in several ways. For example, the mouth and throat sores of mucositis can cause significant pain and make it difficult to eat, drink, and even take oral medication. Mucositis is also accompanied by a severe risk of infection, as it can lead to a breach in the otherwise protective linings of the oral mucosa and gastrointestinal tract, which are colonized by a vast array of microorganisms. Further, efforts to counter the discomforts of mucositis can lead to disruptions in cancer treatment, alterations in treatment dosages, or shifting to different modes of treatment. Severe mucositis can also lead to the need for parenteral nutrition or hospitalization. The development of effective approaches to preventing and treating mucositis is therefore important for improving the care of cancer subjects.
Overall, mucositis affects 15-40 percent of subjects receiving standard-dose chemotherapy and 76-100 percent of subjects receiving higher doses of chemotherapy for bone marrow transplantation. Mucositis also affects virtually all subjects receiving radiation therapy for head and neck cancer, as well as subjects receiving radiation along the GI tract. For example, esophagitis (or esophageal mucositis) is a major complication of chemoradiation therapy in subjects with non-small cell lung cancer that produces significant morbidity and results in treatment interruptions. Mucositis afflicts over 400,000 subjects a year in the US, and the incidence is growing as the need for radiation and chemotherapy treatments grows. This represents a potential annual market of greater than $800 million in the US.
Treatment of oral mucositis is a significant unmet medical need. Current treatment strategies are primarily palliative and include mucosal coating mixtures that may contain topical anesthetics and antibiotics to prevent infection. These treatments provide little benefit, and do not speed healing or decrease severity of mucositis.